1. Field of the Invention
The present invention relates to a crystal oscillator for surface mount, and more particularly, it relates to a surface mount crystal oscillator which can improve productivity and realize miniaturization and a manufacturing method of the same.
2. Description of the Related Art
[Prior Art]
A surface mount crystal oscillator is small-sized and lightweight, and is hence incorporated as a frequency or time reference source in a portable type electronic device.
In a conventional surface mount crystal oscillator, a crystal piece 2 is mounted on a ceramic substrate, and is covered and sealed with an inverted cover having a recessed shape. In recent years, there has been suggested an inexpensive household oscillator having a frequency deviation Δf/f which is comparatively loosely regulated, for example, from ±150 to ±250 ppm.
[Related Art]
It is to be noted that examples of a related prior art include Japanese Patent Application Laid-Open No. 2007-158419 ‘Surface Mount Crystal Oscillator’ (Nihon Dempa Kogyo Co., Ltd.) and Japanese Patent Application Laid-Open No. 2003-179456 ‘Surface Mount Container for Crystal Product and Crystal Product using the Same’ (Nihon Dempa Kogyo Co., Ltd.)
Japanese Patent Application Laid-Open No. 2007-158419 (Patent Document 1) discloses a constitution of a surface mount crystal oscillator in which a crystal piece 3 is mounted on an IC chip 2, the IC chip 2 and the like are formed on a mount substrate 4, and a metal cover 5 is disposed.
Moreover, Japanese Patent Application Laid-Open No. 2003-179456 (Patent Document 2) discloses a constitution of a surface mount container for a crystal product in which a crystal piece 3 is disposed on a single layer substrate 1A via a crystal terminal 6, and is sealed with a cover 2.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2007-158419
[Patent Document 2] Japanese Patent Application Laid-Open No. 2003-179456